2.1 It is generally known within the art of seafood processing that the fresher the seafood, the better the taste. However, the consumer does not always have access to live or fresh seafood. Therefore, fishermen and processors rely to a great extent on refrigeration to prevent spoilage. However, refrigeration alone does not stave off bacteriological degradation of the product for any significant length of time. Various methods have been incorporated into the process for lengthening the time span from catch to consumer, such as packing in brine, thermal blanching, and the introduction of anti-microbial agents. However, to preserve the product for longer periods it is simply cooked prior to being frozen and then kept refrigerated until delivered to the consumer.
2.2 It is also known that reheated foods of any type loose their fresh taste. This is especially true with crustaceans because the fats contained therein are either lost in the cooking process or fail to liquefy when reheated, thus producing rancid or bland tasting product. Most crustaceans have air pockets within their bodies. It is these air pockets that cause the most significant problems associated with freezing the crustacean due to formation of large ice crystals in the pockets that tend to rupture the cell structure of the meat causing frostbite. Therefore, the prior art teaches that for best result the shell or at least the heads and claws of shrimp, lobster, crawfish and crab especially must be removed prior to freezing.
2.3 Even when fresh, unfrozen crustaceans are available to markets and restaurants they must be kept refrigerated, cooked and consumed generally within 48 hours. This leads to sporadic, seasonal markets for such crustaceans.
Spoilage is a constant concern when processing seafood in general and crustaceans in particular. Seafood spoilage is a result of bacteriological colonization on and within the product that begins immediately upon thawing of the product as it passes above 32 degrees Celsius. After the onset of bacteriological colonization the product may become inedible within minutes as result of the high bacteria count within the above-mentioned air pockets within the crustacean. Refrigeration only retards bacteriological colonization. Therefore, to expand the shelf life of whole unshelled, uncooked, crustaceans it is essential that they be as free of bacteria as possible prior to freezing.
The treatment of food products with ozone, in particular seafood, such as fish or crustaceans, and the like, is well known within the art; reference may be made by way of example to the documents Fr-385, 815, EP-294, 502, Fr-797, 928, Ca-2, 102,362, U.S. Pat. No. 4,559,902 or 6,514,459.
One of the applications that is highly promising today is actually the washing of food products with ozonized water, in particular the washing of seafood. These washing operations with ozonized water have been very particularly proposed as replacement for washing with chlorinated water, chlorine being progressively subject to very severe restrictions in this industry.
In these known processes for washing with plain water or optionally chlorinated or ozonized water, dirt and other organic loads from the products. Therefore, a process for sanitizing and disinfecting sea food, in particular crustacean, would seem to help reduce the bacteria count on and within such crustacea provided sufficient retention time is allowed and a sufficient sanitizing bath after disinfecting is applied. In any case, the shellfish should be maintained in good health until ready for final processing. The prior art seems to teach that this is possible.
The prior art such as is taught by Hirsch in U.S. Pat. No. 6,033,701 further teaches that pressures of 10,000 PSI or more can preserve cooked foods for up to a month without refrigeration. As impractical as this may seem, a lesson may be learned in that pressure also tends to retard bacteriological colonization. Further, Voisin in U.S. Pat. No. 6,537,601 teaches that pressures between 10,000 P.S.I. and 60,000 P.S.I. held for 1–15 minutes at an elevated temperature of between 50–130 degrees Fahrenheit can eliminate pathogens and other bacteria from raw shellfish. Voisin further teaches that a seasoning may be injected into the product under the aforementioned pressure. However, such pressure, if applied to uncooked, unshelled, live crustacea would simply crush the shells and partially cook the crustacea making them unusable for distribution as an in-shell fresh frozen product. However, subjecting the crustacea to a much lower pressure could be beneficial. The prior art further teaches, that seafood may be pickled using a preservative and other agents including acidic acids such as vinegar, and lemon juice, thus extending the life of the product without refrigeration for several years. An example of this process is referenced by U.S. Pat. No. 3,985,890. However, such pickling requires that the product be cooked and maintained in a solution. However, some degree of pickling may be useful in uncooked seafood products.
It is also known that aqueous acidic solutions are useful in the biological treatment of seafood without the seafood acquiring any flavor derived from the solution being absorbed by the seafood or a cooked flavor distinctive from the natural cooked flavor of the seafood. These acidic solutions serving as a bactericide are effective in penetrating cell membranes of the spoilage-causing bacteria found in seafood and adversely affect the intracellular pH of the bacteria. By treating seafood with these acidic solutions shelf life of fresh seafood is extended by several days. However, this process as taught by Earle in U.S. Pat. No. 5,273,768 is only recommended for fresh cold water fish that have been eviscerated and washed in fresh water prior to exposure to the acidic solution. No mention is made regarding its effectiveness upon live crustaceans.
Still further, quick freezing seafood is thought to retard or destroy bacteria, however we find that bacteria growth may result from damage to the cell walls and air pockets within the body cavity created by large-crystal formations created when freezing some types of seafood, such as crawfish, due to differences in temperature of the meat and the more dense exoskeleton structure. Therefore, it is essential that proper procedure be used as taught by Bender in U.S. Pat. No. 5,262,186 when freezing crustacea. The above prior art references singularly or taken as a whole fail to teach or otherwise suggest a process for preserving the texture and flavor of raw, unshelled crustaceans that would further extend the shelf life of such products.
2.4 It is, therefore, an object of this invention to provide a method for treating crustaceans in such a manner as to reduce or eliminate bacteriological contaminates and deterioration resulting therefrom and extend the shelf-life of raw unshelled crustaceans by freezing.
2.5 It is another object of this invention to provide uncooked crustaceans to end consumers in bulk or in batch type cook and serve containers, with or without seasoning.